1. Technical Field
The present invention relates to a novel .beta.-lactam type anti-bacterial agent and a pharmaceutically acceptable salt thereof. More particularly, it relates to a novel cephem compound and a pharmaceutically acceptable salt thereof, a process for producing them and an anti-bacterial agent containing them as effective ingredients. The present compound has an excellent therapeutic effect against diseases caused by human or animal pathogens and is useful as a remedy for human and veterinary use.
2. Background Art
Cephem type compounds structurally relevant to the compound according to the present invention include the ones which are disclosed in Japanese Patent Laid-Open Publication Nos. 124790/1980, 122388/1981 and 76083/1984. Also, the compounds which have been discovered by the present inventors and are disclosed in Japanese Patent Laid-Open Publication Nos. 178991/1986, 19593/1987 and 205088/1987 are structurally relevant cephem type compounds, which have a .beta.-substituted vinyl side chain as in the compound of the present invention. However, the compound of the present invention is a novel cephem compound which is different from these known relevant compounds with regard to the substituents of the side chain.
Cephalosporin type antibiotics exhibit wide antibacterial activities against Gram-positive and Gram-negative bacteria. A variety of semi-synthetic cephalosporin type compounds are now commercially available and have clinical uses as remedies against infectious diseases. However, among those compounds, very few exhibits anti-bacterial activity against Pseudomonas aeruginosa or Myxomycetes, and many of these compounds are unstable to .beta.-lactamase which is produced by a resistant bacterium and thus have drawbacks in a low anti-bacterial activity against resistant bacterium which is a serious problem on clinical therapies (W. E. Wick, Chapter 11 in "Cephalosporins and Penicillins, Chemistry and Biology", edited by E. H. Flynn, Academic Press, New York, N.Y., 1972).